The average height of European men grew by a surprising 11 centimetres from the early 1870s to 1980, reflecting significant improvements in health across the region, according to new research published on Monday.

Contrary to expectations, the study also found that average height accelerated in the period spanning the two World Wars and the Great Depression, when poverty, food rationing and hardship of war might have been expected to limit people's growth.

The swift advance may have been due to people deciding to have fewer children in this period, the researchers said, and smaller family size has previously been found to be linked to increasing average height.

"Increases in human stature are a key indicator of improvements in the average health of populations," said Timothy Hatton, a professor economics at Britain's University of Essex who led the study.

He said the evidence - which shows the average height of a European male growing from 167 cm to 178 cm in a little over a 100 years - suggests an environment of improving health and decreasing disease "is the single most important factor driving the increase in height".

The study, published online in the journal Oxford Economic Papers, analysed data on average men's height at around the age of 21 from the 1870s up to around 1980 in 15 European countries.

The study only looked at men, the researchers said, because extensive historical data on women's heights is hard to come by.

For the most recent decades, the data on men were mainly taken from height-by-age surveys, while for the earlier years the analysis used data for the heights of military conscripts and recruits.

On average, men's height had grown by 11 cm in just over a century, the researchers found, but there were differences from country to country.

In Spain, for example, average male height rose by around 12 cm from just under 163 cm in 1871-1875 to just under 175 cm in 1971-5, while in Sweden, men's average height increased by 10 cm from just over 170 cm to almost 180 cm in the same period.

The researchers found that in many European countries - including Britain and Ireland, the Scandinavian countries, Netherlands, Austria, Belgium and Germany - there was a "distinct quickening" in the pace of advance in the period spanning the two World Wars and the Great Depression.

"This is striking because the period largely predates the wide implementation of major breakthroughs in modern medicine and national health services," they wrote.

Hatton said one possible reason, alongside the decline in infant mortality, for the rapid growth of average male height in this period was that there was a strong downward trend in fertility at the time - and smaller family sizes have previously been found to be linked to increasing height.

Other height-boosting factors included higher per capita incomes, more sanitary housing and living conditions, better education about health and nutrition and better social services and health systems. - Reuters